Distribution of the viable counts of lactobacilli in plaques dosed with (DA) and without (DN) arginine dentifrice in the presence (C) and absence (R) of sucrose. Box plots: red, DN with sucrose; cyan, DA with sucrose; green, DN without sucrose; magenta, DA without sucrose. For details, see the legend to Fig. 1. DN plaque counts in the presence of sucrose were significantly (P < 0.001) higher than DN and DA plaque counts in the absence of sucrose. DN counts in the absence of sucrose were significantly (P < 0.001) higher than DA plaque counts in the absence of sucrose. Counts of lactobacilli were significantly (P < 0.001) higher in cariogenic plaques dosed with DN and with DA. Resting plaques dosed with DN had significantly (P < 0.001) higher counts of lactobacilli than those dosed with DA.